This study was designed to determine the effect of mind mapping on students? achievement in abstract contents of electrical and electronic trades in technical colleges. The study adopted the quasi-experimental research design, precisely, pretest, posttest non-equivalent control group design which involved groups of students in their intact classes. A sample of 193 electrical and electronic trade year II students drawn by multistage sampling technique from a population of 354 from eight technical colleges in Ogun state was used for the study. Four research questions and four null hypotheses tested at 0.05 level of significance guided the study. Electrical Electronics Achievement Test (EEAT) is the instrument used for data collection. The EEAT and lesson plans for both control and experimental were all subjected to face and content validation by three experts. The reliability coefficient of the instrument was computed using KR-20 and found to be 0.81. Mean was used to answer the research questions, while Analysis of Covariance (ANCOVA) was employed to test the hypotheses. The study revealed that mind mapping instructional strategy was superior to the conventional method in enhancing student achievement in abstract contents. It also discovered that gender grouping did not contribute significantly to variance in students achievement score, thus the effectiveness of mind mapping does not depend on gender. After pointing out some educational implications of the findings, it was thereafter recommended that mind mapping should be adopted in teaching abstract contents of electrical and electronic trades.